Among livestock, such as cattle, pigs, goats, sheep, poultry and/or horses, as well as in pets, the administration, in particular by injection, of products for therapeutic, prophylactic or metaphylactic purposes for anti-infection purposes is frequent.
The volume of product administered parenterally and the number of injection sites are important criteria in the choice of a formulation. One objective of producing a concentrated formula is to reduce the volume and/or the number of administrations, in particular with a view to reducing, for livestock, the muscular areas not able to be processed in the abattoir. Another important criterion, which may also be taken into account in the production of concentrated formulae, is the local tolerance, at the injection site, in particular for reducing losses at the abattoir.
However, some anti-infection products, for example marbofloxacin, have low solubility in water. This may lead to using technologies for increasing their solubility, such as salification, the use of complexes more soluble than the molecule itself, for example in combination with a cyclodextrin, pH modifiers, dispersed systems (emulsions, liposomes, vector systems), or the addition of adjuvants such as organic solvents, co-solvents or surfactants.
However, the techniques mentioned above may have very relative efficacy compared with certain specific compounds.
Among the solutions marketed, stable solutions containing up to 10% marbofloxacin can be cited. However, for certain therapeutic, prophylactic or metaphylactic indications, in particular in livestock, the therapeutic dose is high. Thus the use of solutions currently marketed requires the administration of large injection volumes, in particular greater than or equal to 40 ml, distributed in several injection sites. These conditions may lead to problems of tolerance.
EP 0 868 183 describes concentrated pharmaceutical aqueous solutions of danofloxacin comprising metallic salts, the tolerance of which, at the injection site, is said to be improved.
However, this type of formulation, previously prescribed for tetracyclins, may prove not to be applicable to or in any case not sufficiently effective with respect to every type of molecule, in particular with regard to certain quinolones.
However, for various reasons, including the improvement of animal wellbeing, a saving in time and/or improvement in meat yield, it may be desirable to reduce the volume of product administered parenterally or the number of injection sites and/or to improve the tolerance.
There therefore still exists a need for concentrated formulae of anti-infection compounds, in particular of the quinolone type, making it possible to reduce the volume or the number of administrations and/or having improved tolerance, thus being able, for livestock, to reduce the unusable muscular areas.